47 lines
771 B
Text
47 lines
771 B
Text
import extensions;
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import system'routines;
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class Operable
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{
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Operable = self;
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operate()
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= "delegate implementation";
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}
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class Delegator
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{
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object? Delegate : prop;
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constructor()
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{
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Delegate := nil
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}
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operate()
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{
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// if the object does not support "Operable" message - returns nil
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var operable := Delegate?.Operable \ back(nil);
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if (nil == operable)
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{
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^ "default implementation"
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}
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else
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{
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^ operable.operate()
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}
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}
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}
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public Program()
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{
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var delegator := new Delegator();
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new object[]{nil, new Object(), new Operable()}.forEach::(o)
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{
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delegator.Delegate := o;
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Console.printLine(delegator.operate())
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}
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}
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